MIL-DTL-38999 Series II connectors are designed for harsh environments, featuring up to 128 contacts in an insert with front wall mount, rear wall mount, jam nut, rear box mount, and front box mount receptacles. Operating in temperatures ranging from -65 °C to 200 °C, these connectors offer reliability in extreme conditions. Available in 9 shell sizes and 52 insert arrangements, they use M39029 rear release crimp contacts for secure connections. Crafted from durable aluminum, with plating options including electroless nickel and cadmium finishes, these connectors ensure longevity and performance. Suitable for military and industrial applications, they meet rigorous standards for conductivity, ingress protection, and environmental resilience.